Hexagonal system optical properties

A seemingly trivial variation in the procedure can affect the particle crystallinity and optical properties for the CdS nanoparticles prepared in a AOT/heptane/water [215] system. It is reported that on mixing different volumes (5 ml and 15 ml) of w/o microemulsion solutions, while keeping all other parameters (viz. AOT concentration, aqueous salts concentration. Wo (= 4), time of mixing and temperature) constant nanocrystalhtes with similar size (3.8 and 4 nm) but different crystalline structures (namely, cubic and hexagonal) of CdS are obtained. 

The difficulty in direct synthesis of mesoporous transition metal oxides by soft templating (surfactant micelles) arises from their air- and moisture-sensitive sol-gel chemistry [4,10,11]. On the other hand, mesoporous silica materials can be synthesized in nimierous different solvent systems (i.e., water or water-alcohol mixtures), various synthetic conditions (Le., acidic or basic, various concentration and temperature ranges), and in the presence of organic (Le., TMB) and inorganic additives (e.g., CT, SO, and NOs ) [12-15]. The flexibility in synthesis conditions allows one to synthesize mesoporous silica materials with tunable pore sizes (2-50 nm), mesostructures (Le., 2D Hexagonal, FCC, and BCC), bimodal porosity, and morphologies (Le., spheres, rods, ropes, and cubes) [12,14,16-19]. Such a control on the physicochemical parameters of mesoporous TM oxides is desired for enhanced catalytic, electronic, magnetic, and optical properties. Therefore, use... 

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